Opera has long felt quicker than other browsers do, and that won it many fans. The competition is much tighter now: Both Safari and Firefox 3 show impressive speed. Still, Opera 9.5 markedly improves on the performance of the previous version, 9.27. I ran the SunSpider JavaScript Benchmark, which takes browsers through a comprehensive battery of scripts that its makers claim address real-world tasks, ranging from screen drawing to encryption to text manipulation. I ran the tests on a Windows Vista Ultimate machine with a 2.4-GHz Athlon 64 processor. Opera 9.5 outstrips the previous version, taking only 9,202 milliseconds (the average of three trials), compared with Version 9.27's 12,625 ms. It does fall behind the latest Firefox, which, at 4,728 ms, is nearly twice as fast, but it still shellacs Internet Explorer 7, which took 151,783 ms.

In another rendering-speed challenge, I used QuirksMode.org's DOM 1, which measures the time the browser needs to create a large table using W3C DOM methods. Opera came out on top, taking an average of 55 ms over ten runs, while Firefox 3 took 245 ms and IE took 1,352 ms.

How long a browser takes to start up is an important measure of performance. I timed Opera starting up coldafter a reboot, in other wordsand warm, after it had already been run once. It did remarkably well, taking an average of only 2.7 seconds cold, handily beating Firefox 3's ponderous 12.6, Internet Explorer's 5 seconds, and its own previous version's 5.4.

Memory use is another factor that affects how smoothly your PC will perform when you're running a browser. I checked memory usage under Vista, which reports the private working set (the actual memory the app is using), by loading the same ten media-rich Web pages at once on each browser. Opera required a frugal 88MB, but Firefox 3 has really tightened up in this area, taking only 65MB. Both, however, trounce Internet Explorer, which hogged 210MB.Next: Standards Support

Michael Muchmore is PC Magazine’s lead analyst for software and Web applications. A native New Yorker, he has at various times headed up PC Magazine’s coverage of Web development, enterprise software, and display technologies. Michael...

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